Rotary bladed structure



R. M. SHERMAN ET AL HLW ROTARY BLADED STRUCTURE Original Filed Dec. 27, 19:554 2 Sheetsheet l 3l En@ /avtsa as W V//// y y MLM? Mam/mich 22, 1938.

R. M. SHERMAN ET AL ROTARY BLADED STRUCTURE Original Filed Deo. 2'?, 1935 2 Sheets-Shaw.` 2

Patented Mar. 22, 193s .UNlTEo ySTATES PATENT OFFICE l .I `incitant! nzlsinsraucruna l Carlberg and George R.- Neumann,

assignors to The Silent` Hartford, Conn.,

Glow Oil Burner Corporation,

West

Hartford,

Conn., a 'corporation of Connecticut e claims. (c1. 23o-114i others, is to provide a rotary impeller of simple mouth of the conduit. At' the air receiving end 5 construction and particularly for the purpose of of the casi-ng there is provided a sleeve I3 teledelivering air or other gaseous iiuid, said im- Y scopically fltting the rear end of the tubular peller having blades which are movable each on member 9, this sleeve, serving the function vof an axis extending outwardly` from the axis of surrounding the impeller 'l and also ofsupport'- rotation and movement of which may be useing the motor I5 employed for driving the im.- 10 fully availedof to rv-cut off, as may be required, peller. The motor casing is supported by the further substantial passage of fluid on the stopsleeve I3 through a plurality of equally spaced page of: the impeller-'or to adjust the working arms I9 (herein four in number), formed intepitch vof the blades to vary the capacity of the 'grally with the sleeve and extending part way impeller. V radially inward, eacharm carrying a laterally 15 Another object of the invention is to provide a extending lug 2l bolted to a boss on the motor rotary structure having movable blades of such casing. The shape and arrangement of such size, shape and relation as to form a substantial supporting lugs are best indicated in Figs. 4 and f closure for an air delivery or other aperture, the 5. This arrangement suspends the motor ontthe blades, whether or not having any air impelling y supporting sleeve in overhanging relation with- 2o function, being movable in response to the rotain the casing 9, leaving an annular space between tion 0f the structure 'to open said aperture and the cylindrical-casing and the motor to serve as to close the latter on the stoppage of rotation. a partcf the air conduit. The faces 23 of the These and other objects of the invention will arms I9, which confront the closely adjacent 25 be best understood by reference to the following rotating blades of the air impeller, serve as air 25 description when .taken in connection with the. cut-,0i means. aS hereinafter more fully eX- accompanying illustration of one specific emplained'.` The inner walls of the sleeve I3 are bodiment thereof, while its scope will be more v tapered inwardly and-forwardly, -providing a particularly 'pointed out in the appended claims. bore having a contracted air delivery mouth or In the drawings: I aperture closely surrounding the blades of the 30 Fig. 1 is aside elevation, partly broken away, fan or impeller, as shown in Figi 1- showing an air impeller fanwith the blades 'Ihe described arrangement'is merely illustraclosed, and also showing the' relation of the fan tive as one application of the invention, the spe-v to the surrounding 'Walls of an air conduit and cie mounting of the motor and its relation to to a driving motor; y A ,the fan being immaterial, the specic type o f 35 1 Fig. 2 1s a. simuar side 'elevation showing' the air conduit being unimportant, and the same beblades open; j ing employed to illustrate one form of air deliv- Fig. 3 is a front elevation in partial section ery aperture, such as the mouth of the sleeve I3,

' showing the air fan with the Ablades irrclosed through which the air impeller 1S designed t0 .40 position, looking from the open or air entering .control the delivery of air. 40 end; Q Referring more particularly to theconstruction fFig. 4jis a 'section'in elevation, taken on the, of the air impeller, as best shown in Figs. 1, 2, line 4 4, showing the motor with its' supporting 3, and 6, the same is provided with a sleeve-like means; v hub 25 secured to the rearwardly projecting end Fig. 5 is a'detail in cross-section, on the `line t of the motor shaft 21. The fan or impeller Icom- 45 5 5, showingone of the mctorsupporting lugs; prises a seriesof thin, light, metallic blades 29 and v I (herein six in number), approximately flat but Fig.` 6 is an elevation showing the impeller, slightly concaved toward the air delivery side of looking from the delivery side, also with theV the fan, each-blade being of a generallytriangu- 60 blades in closed position. v lar'shape with an outer arc-shaped edge. Each 50 In the embodiment of the invention selected blade at the inner and outer ends of one edge -for illustration, there is shown in, the drawings has a small corner flange 3| bent at right angles,

a rotary air impeller 1 of the propeller or pitched by means of which the blade i's pivotally mounted .blade type, designed in this particulaase to on a pin orsmall rod 33 and on which it is held deliver air 'to the combustion chamber of a fur- This invention'relates to rotary'bladed struc# tures, and is a division of our application, Serial No. 56,334, led December 27, 1935. f One object of the present invention, among nace in connection with an oil burner, the cylindrical body or casing 9 representing the tubular vair conduiti'or an oil burner, through which air passes from the entering end II to the delivery by a small dish-shaped cap piece 35-xedly sesecured to the fanhub 25 and projects outwardly therefrom but is also pitched or inclined somev what forwardly in the direction of air delivery and with relation to the axis of rotation of the impeller.

A torsion spring 31 encircles each pin, having one end xed to the pin and the other end extending over and lying against the face of the adjacent fan blade so that normally, when the fan is at rest, the blades are urged by the light pressure of the spring in a direction to `cause them to assume a closed position, or that shown in Figs. 1, 3, and 6, in which position they are each'maintained by the smali stop nger 39 projecting from the lower end of the free side of the blade. In the described relationship this finger encounters and is stopped by the pivoting pin 33 of the next adjoining blade.

'Ihe pivotededge of each blade extends somewhat beyond the pivoting rod, and when thel blades are in closed position this extension is there overlapped by the free edge of the next adjoining blade. Accordingly, when the fan is at rest and the blades closed, the latter form a substantially continuous closure in the general form of a truncated cone, substantially closing the'air delivery aperture of the sleeve I3, as best seen in Fig. 1, there being left between the edges of the blades and the walls of such aperture only a reasonable mechanical clearance to permit the rotation of the fan and the subsequent opening movement of the blades.

When the fan is started into rotation, however. the forward inclination of the pivotal axes of the blades causes the latter to move under centrifugal force about the pivot pins and to open up against the opposing. pressure of vthe spring 31- into some such position as is representedin Fig. 2. This opening movement continues -as the speed of rotation increases, until either positively arrested or until the center of gravity of each blade reaches its maximum radial distance from the axis of rotation. As soon as the opening movement of the blades has been initiated under centrifugal force, it is further aided by the reaction of the air across which the blades are thencutting. The walls of the air conduit within the sleeve are enlarged by being rearwardly flared to permit the required opening movement of the blades while closely surrounding the latter in all positions assumed.v

The angular inclination of the blade axes to the axis of rotation may be varied within wide limits, dependent on the weight of the blades, the position of the center of gravity of each and the strength of the closing spring to be overcome.

With a relatively heavy blade or with one blade or a heavier spring, a greater inclination may be required. With light sheet metal blades of the form shown and a relatively light spring, we have found that an angle of inclination of the order of approximately 25 (as shown in the drawings) insures a positive, certain opening of the blades when the impeller is rotated at speeds of the order of 500 R. P. M. or more.

The working pitch of the blades and the resulting capacity of the fan for air delivery are dependent on the extent of this opening movement. Thismay be predetermined and the air supply definitely fixed by the simple use of an adjustable blade stop. 'I'his is herein provided by means of the sleeve 4| (Figs. 1 .and 2) which is adjustably threaded on the outside of the fan hub 25 and has its forward-edge presented to the -stop finger 3l of each blade, as shown in Fig. 2. The stop 4| may be adjusted to any desired position lengthwise the threaded portion of the fan hub and there held fixed by the set screw 43, thereby providing means whereby the opening movement of the blades may be'adjusted to any point between zero opening and maximum. The air supply may `therefore be preadjufs'ted by the adjustment of the fan alone and without the use of any valve or shutter extraneous to the fan.

The use of the self-closing air impeller blades provides the important function of automatically stopping further passage of air through the air delivery aperture as soon as the fan ceases to function in creating its forced draft. When the fan is at rest, it eiects a substantial closure of the air conduit and automatically seals off the aperture against the passage of air. f

To accelerate the progressivemovement of the air from the air entering endll through the air delivery aperture and the conduit, which air movement would otherwise in part tend to rotate without progression, the air cut-ois 23 on the arms I9 are employed which lie immediately in front of the fan and project radially across the annular path of the rotating body of air as it leaves the fan, the impeller rotating in a clockwise direction as viewed from the front in Fig. 4. If the number or effectiveness of such cut-oil members is increased, the rotary movement of the air is diminished and its progressive movement further increased.

Claims relating to the cooperative relationship between the features of the rotary bladed structure and those of the liquid fuel burner are separately claimed in application, Serial No. 56,334, of which this is a division. Certain features of improvement not herein disclosed are claimed in the subsequently filed co-pending application of Sherman and Carlberg, Serial No. 138,604, filed April 23, 1937.

While we have herein shown and described for the purposes of illustration one specific embodiment of the invention and one specific application thereof, it is to be understood that the latter has application to a wide variety of uses and, furthermore, that extensive changes may be made in the form, relative arrangement and details of the parts vherein shown, all without departing from the spirit of the invention.

We claim:

1. The combination with an air delivery conduit having an air delivery aperture, of a rotary air impeller in said conduit in operative relation to said aperture, said impeller having blades rotatable each about an outwardly extending axis inclined with relation to the axis of impeller rotation, and mounted to turn to an air-impelling position in response to rotation of the impeller, said blades being of such size, shape and relation as to form a substantial closure for said aperture, and means for automatically moving said blades to a closed position when said impeller is at rest, whereby, when said impeller is at rest, said aperture is substantially closed and when .rotated said blades are swung about their axes and opened to an air impelling position.

2. A rotatableair impeller having a plurality of blades rotatable each about an outwardly directed axis and mounted to turn to an air-impelling position in response to centrifugal force on rotation of the impeller, the blades being oi lsuch size, shape and relation as to forma substantial closure for an air delivery aperture in relation to which the impeller may be operatively positioned, the axis of each blade being inclined with relation to the axis of rotation of the impeller, and means for automatically moving said blades to a closed position when said im- 'peller is at restwhereby, on rotation of the impeller, the blades are opened by centrifugal force to an air impelling position and onv stoppage thereof are moved to a closed position.

3. A rotatable air impeller having a plurality of blades rotatable each about an outwardly Idirected axis, and mounted to turn to an air-impelling position in response to rotation of the impeller, the blades being of such size, shape and relation as to form a substantial closure for` an Iair delivery'aperture in relation to which the structurel is operatively positioned, the axis of each blade being inclined with relation to the axis of rotation .if said structure, and means for automatically moving said blades to an aperture-closing position when said impeller is at rest, whereby on rotation of the Vstructure the blades are opened by centrifugal force to an aperture-opening position and on stoppage thereof are moved to an aperture-closing position.

4. The combination witha structure presenting an air supply aperture, yoi? a rotatable stmoture inoperative relation thereto carrying a series of blade sections pivoted each near one edge on an axis extending outwardly from and inclined to the axis of rotation of said carrying structure. the free edge of one blade section overlapping the pivoted edge of the next adjacent blade section, said blade sections being of such size, shape and relation as to form a substantial closure lifor Vsaid aperture when said carrying structure is at rest, means for urging said blade sections into over-lapping and aperture closing relation on the stoppage of rotation of said carrying structure, said blades being adapted on rotation of said carrying 'structure to move under centrifugal force to an aperture opening position, and means to rotate said structure.

5. The combination withy a structure present` ing an` air supply aperture, of a rotatable structure operatively related to said aperture and carrying a plurality of blades mounted to turn each about an outwardly extending axis inclined with relation to the axis of rotation of said carrying structure, said blades being of such size, shape and relation as to form a substantialv closure for said aperture when moved to one p oslv tion, means to rotate said structure, and means acting automatically on the stoppage of rotation of said structure to move said blades t0 maintainan aperture closing position, said blades being automatically movable inl response to the rotation of the carrying structure to move to an aperture opening position.

6. The combination with a structure presenting an air supply aperture, of a rotatable air impeller in operative relation to said aperture and having a plurality of impelling blades mounted each to turn about an axis extending outwardly from the axis of rotation of the impeller, means aided by centrifugal force for causing the automatic movement of the blades about their axes on rotation of the impeller` to an aperture opening andair impelling position, said blades being of such size, shape and relation to the aperture as to form a substantial closure therefor when moved to another position, means acting automatically on the stoppage of the impeller rotation to move said blades to maintain an aperture closing position, andimeans for rotating said impeller. y Y

'7. The combination with a structure presenting an air supply aperture, of a rotatable structure, in operative relation thereto and having a plurality of blades movably mounted on said rotatable structure, -means aided by centrifugal force :for :causing the automatic movement of the blades to an aperture opening positionon rotation of the rotatable structure, said blades being of such size, shape and relation to the apertureas to form a substantial closure therefor when moved' to another position, means acting automatically on the stoppage of rotation of such rotatable structure to` move the blades to maintain an aperture closing position, andA means for rotating said rotatable structure.

I 8. The combination with a structure having an aperture, of a rotatable impeller in operative relation thereto and having a series of concavoconvex bladesv mounted each on an axis at the convex side of the blade near one edge thereof, said axis extending outwardly from but inclined tothe axis of rotation, said blades being normally moved to an overlapping position to form `a conical structure substantially closing said aperture, and said blades being each movable about its axis under centrifugal force to open said aperture when the impeller is rotated.

, RALLSTON M. SHERMAN.

JOHN CARLBERG. GEORGE R. NEUMANN. 

